Carpet stretcher



Dec. 19, 1967 G. A. KocHANowsKl 3,359,032

CARPET STRETCHER Filed Nov. l5, 1965 3 Sheets-Sheet l Dec. 19, 1967 G. A. KocHANowsK| 3,359,032

v CARPET STRETCHER Filed Nov. 15, 1965 5 sheets-sheet Dec. 19, 1967 G. A. KocHANowsKl 3,359,032

CARPET STRETCHER Filed Nov. l5, 1965 3 Sheets-SheerI 5 A a p),

7L/ ks Mll" 422/.

nited States Patent O 3,359,032 CARPET STRETCHER George A. Kochanowski, Chicago, Ill., assignor to Kinkead Industries, Incorporated, Chicago, Ill., a corporation of Illinois Filed Nov. 15, 1965, Ser. No. 507,936 9 Claims. (Cl. 2948.6)

ABSTRACT F THE DISCLOSURE A carpet stretcher of the type commonly referred to as a kicker having a set of carpet engaging pins with a guard plate and a stop in the path of movement of the plate to position it for the desired degree of pin extension.

In installing carpeting wall-to-wall it is desirable to stretch the carpet between anchoring strips in order to avoid formation of wrinkles as the carpet is used. The stretchers in most common use employ sharpened pins mounted in a head which is either positively moved with respect to some remote point of anchoring, such as the opposite wall of the room, or which is secured by a handle to a kicking pad struck by the knee of the carpet installer. In both types of stretchers it is known to provide means for adjusting the degree of relative extension of the pins so that the tips of the pins engage the carpet backing without penetrating into the underlying cushioning pad. Prior stretchers of the adjustable type have been dicult to adjust to a given height of pile, have been subject to cocking and binding of the plate carrying the pins, and have been of relatively expensive construction.

It is accordingly an object of the present invention to provide a carpet stretcher which overcomes the disadvantages of conventional stretchers, which is inherently strong and long-lived, and which is easy to use and adjust.

It is a more specific object of the invention to provide a carpet stretcher which is safe to use and transport and in which the sharpened tips of the pins are shielded or protected at all times when the stretcher is not in actual working engagement with the carpet. In this connection it is an object to provide a carpet stretcher having a set of carpet pins which are normally shielded but which are automatically exposed or extended to the desired degree when the usual downward force is applied for gripping of the carpet before kicking or application of the stretching force.

It is an object of the invention to provide a structure which is simple and durable and in which the plate which supports the pins is rigid and integral with the frame permitting a much larger force to be applied to the pins, without risk, than has been possible in the past.

It is another object of the invention in one of its aspects to provide a carpet stretcher having novel provision for varying the degree of projection of the pins including improved means for establishing a more positive reference for adjustment purposes, enabling the device to be used with carpets having a Wide range of height of pile and to reduce the need for constant judgment.

It is yet another object to provide a stretcher which possesses the above advantages but which may be economically manufactured.

Other objects and advantages of the invention will become apparent upon reading the attached detailed description and upon reference to the drawings in which:

FIGURE 1 is a top view, in partial section, of a carpet stretching device, or kicker, constructed in accordance with the present invention.

FIG. 2 is a fragmentary perspective showing the external appearance of the head portion of the device shown in FIG. l.

3,359,932 Patented Dec. 19, 1967 FIG. 3 is a fragmentary section looking along the line 3 3 in FIG. 1 and with the tips of the pins enclosed or shielded.

FIG. 4 is a section similar to FIG. 3 but showing the guard plate depressed and the pins exposed under working conditions.

FIG. 5 is a fragmentary top view with the upper portion of the head broken away to reveal the guard plate return spring and spring mounting.

FIG. 6 shows a transverse section taken along the line 6--6 in FIG. 5.

FIG. 7 shows the underside of the head with the guard plate broken away and taken along line 7 7 in FIG. 3.

FIG. 8 is a bottom view of the guard plate and looking along line 8 8 in FIG. 3.

FIG. 9 is a diagram showing the effect of the protuberances on the guard plate.

FIG. l() is an enlarged fragmentary section taken through the handle of the device and looking along line 9-9 in FIG. 1.

While the invention has been described in connection with a preferred embodiment, it will be understood that I do not intend to be limited by the embodiment shown but intend to cover the various alternative and equivalent constructions included within the spirit and scope of the appended claims.

Turning now to the drawings there is shown in FIG- URES 1 and 2 a carpet stretcher in the form of a kicker having a head 10, an integral handle 11 and a knee pad 12. The head includes a hollow frame member 15, which may be an aluminum casting, having a side wall 16 defining an internal space 17 and terminating in a lower edge 18. Within the side wall are integral mounting pads 21e24 having mounting screws 25-28 threaded therein. Contained within the space 17, and secured by the screws 25-28, is a pin plate 30 having pins arranged in parallel rows 31-36 inclusive (see FIGS. 6 and 7) projecting forwardly as well as downwardly and preferably terminating in a common plane 37 (see FIG. 4). The pins are of hardened steel pressed into angled openings formed in the underside of the pin plate. To facilitate drilling the holes at an angle, the bottom surface of the pin plate may be stepped as indicated at 38.

For the purpose of adjusting the effective length or degree of extension of the pins, a guard plate 40 is provided underlying the pin plate and having longitudinal slots 41- 46 providing clearance for the rows of pins 31-35 respectively. Such guard plate has an undersurface 47 lying in a plane and an upraised ange or rim 48 which surrounds, and nestingly receives, the lower periphery 18 of the frame member 15. Sufficient clearance is provided between the front edges of the two members, as indicated at 49, to accommodate a limited amount of longitudinal motion between them, as will become clear as the discussion proceeds.

For the purpose of maintaining the guard plate parallel to the pin plate while varying the spacing between them, a parallelogram linkage is used including short vertical links transversely pinned to the guard plate and pin plate, or frame, respectively. In the present instance such linkage includes vertical links 51-52 located at the forward edge of the pin plate and a vertical link 53 located at the rear edge of the pin plate (see FIGS. 3 and 7). The term vertical is used for convenience to distinguish them from the horizontal elements of the parallelogram, and it will be understood that the links in operation swing from a near vertical position to a near horizontal position.

For enabling the guard plate to swing upwardly into a working position close to the pin plate, and to provide accommodation for the links 51, 52, the front edge of the pin plate is relieved to form a central throat 54 anked by forward extensions or brackets S5, 56 respectively. A

pivot pin 57 transversely mounted in the brackets serves to suspend the links 51, 52. For the purpose of pinning the opposite, or lower, ends of the links 51, 52 to the guard plate, the guard plate has integral pin mounts or bosses 61, 62 engaged by a pivot pin 63. Similarly, for supporting the rear edge of the guard plate, the third vertical link 53 is engaged by a pivot pin 70 which extends transversely across a throat 71 formed in the pin plate. At the lower end of the link 53 a pin 72 is arranged transversely in upstanding bosses 7 3, 74 which are integral with the guard plate and which are bridged by an integral bridge 75 (see FIG. 6). It will be understood that the pivot pins which support the links are equipped with snap rings or equivalent at the ends to hold them captive.

It will be apparent, then, that the links 51, 52, acting together, form one vertical link of a parallelogram, the link 53 forms the second vertical link, with the parallelogram being completed by the pin plate and guard plate respectively, Using such a linkage the guard plate is constrained to move toward and away from the pin plate while constantly maintaining a condition of parallelism.

In order to engage the guard plate to deiine a working position, the frame includes a bottoming stop which is arranged in the path of inward movement of the guard plate. In the present instance the stop is in the form of an adjusting screw 80 having a tip 81 and a knob 82 at its upper end. The screw is threaded into a tapped hole 83 in a bushing 84 mounted at the center of the pin plate. A coil spring 85, which surrounds the upper portion of the adjusting screw below the knob, insures suicient friction so that the adjusting screw, once set, does not tend to change its adjustment. For the purpose of recessing the knob 82, the frame of the stretcher may be provided with a central cylindrical opening 86 having a diameter which slightly exceeds the diameter of the knob.

In accordance with one of the aspects of the present invention, a spring is provided, interposed between the frame and the guard plate, for biasing the guard plate outwardly to an extended position in which the tips of the carpet engaging pins are protectively surrounded and which is designed to yield when the tool is pressed against the carpet. This function is accomplished in the present instance by a coil spring 90, which is anchored at its ends 91, 92 to the upper side of the pin plate using suitable machine screws, and with the center of the spring being passed about a vertical pillar on the guard plate. The pillar, indicated at 95, is preferably centered on the bridge 75 previously mentioned. Studs 96, 97, projecting upwardly from the bridge, cooperate with the pillar 95 to provide a curved pocket for the central portion of the spring. It will be apparent, then, with the spring in tension, the guard plate 40 will tend to be urged forwardly and downwardly about the links 51-53 on which it is supported. Such downward movement continues until the tips of the pins are shielded as shown in FIG. 3, whereupon bottoming occurs at stops 98 which tiank the rear link 53 and which are preferably cushioned by suitable pads, or inserts, made of rubber. It will be apparent that with the guard plate occupying its outermost position (FIG. 3) during periods of non-use, the sharpened tips of the pins can do no damage to the user or to other tools or apparatus in the tool bag.

However, when the tool is placed on top of the carpet and downward force is applied to engage the pins in the carpet backing, the reaction force of the carpet pile causes the guard plate 40 to be swung upwardly about its supporting links 51-53 until the upper surface of the plate bottoms against the lower tip 81 of the adjusting screw, thus holding the guard plate with the sharpened pins extended just the right amount for the carpet being worked on. With the pins seated, and with the handle 11 grasped firmly, the operators knee may be swung against the -pad 12 with a hammer-like blow, causing the carpet to be progressively stretched in the forward direction.

When the kicker is picked up for re-positioning, the guard plate 40 resumes its outermost position urged by the spring 90.

It is one of the features of the present invention that spaced protuberances are formed on the underside 47 of the guard plate and occupying a minor fraction of the guard plate area so that localized compressive force is applied to spaced regions of the carpet pile to serve as a more precise reference for the degree of extension of the carpet-engaging pins. Preferably the spaced protuberances are in the form of upraised lands 41a-46a surrounding the slots 41-46. When the lower surface of the guard plate is pressed against the pile of the carpet the protuberances will tend to penetrate the pile to a depth adjacent the carpet backing. It is found that this provides a more positive support, or base of reference, for the pins, even when using the tool with deep-pile carpet. The ptotuberances make the degree of relative pin extension less critical and the operation of the tool less subject to variations in downwardly applied force than would be the case if the protuberances were omitted.

Thus, referring to FIG. 9, the carpet indicated at will be assumed to have a pile or nap 101 and a durable backing 102. The amount of compressive force for each small unit of area is indicated by the density of the stip pling in this diagram. Taking the protuberance 44a by way of example, the carpet fibers lying directly below are highly compressed as indicated by the stippling 103 where= as, in regions 104 centered between the protuberances, the unit pressure is substantially less.

The function of the protuberances may be described, it desired, in terms of spring rate. In the case of a carpet having an exceedingly deep pile, even relatively small changes in the force per unit area applied to the upper surface of the pile are effective to change the depth of penetration, i.e., the height at which a load is supported relative to the carpet backing. Such a carpet can be said to have a low spring rate. However, in the case of carpet at the opposite extreme, carpet having an exceedingly short and dense` pile, variations in applied pressure make very little difference in the height at which the load is supported above the backing. Such carpet may be said to have a high spring rate. By using spaced protuberances which extend downwardly into a deep-pile carpet to a position more closely adjacent the backing, the spring rate of the long pile carpet is effectively increased to a value which is more characteristic of carpeting having a medium or short pile. Moreover, it is -found that the desired amount of pin projection can be more effectively judged by the carpet installer by eying the distance d1 (see FIG. 6) than by eyeing the distance d2. In other words, the distance d1. being shorter than the distance d2, may be visually gauged with a higher order of accuracy, especially by an installer of limited experience.

While the protuberances in the preferred embodiment are of slightly different etective heights, this is simply a matter of designers choice and, if desired, the protuberances may be all at the same height relative to the nominal undersurface 47 of the guard plate. Moreover, while protuberances having a certain total projected area are shown in the drawings, the area may be further reduced, or concentrated, and the height of the protuberances fur ther increased, to provide an increased relative penetration for a given applied force, and hence enabling a still further improvement in gauging accuracy. The only 1imi tation is the temporary patterning which may be left in the pile or nap when the tool is removed.

For the purpose of changing the effective length of the handle 11, such handle is formed in two telescoping parts, an outer tube 111 and an inner tube 112 which may be locked together in an adjusted position by means of a collet 113. Such collet is formed with a plurality of fingers as indicated at 114, 115 having enlarged tips 116, 117. Such tips are selectively received in annular grooves 118 75 formed at spaced intervals on the inner tube 112. For se;

curing the collet to the outer tube, the collet is provided with a threaded sleeve 120 which holds captive a flange 121 formed on the end of the outer tube.

To adjust the length of the handle, therefore, the threaded sleeve 120 is unscrewed permitting the inner tube 112 to be retracted. The collet is then shifted into engagement with an adjacent groove whereupon the inner tube is telescoped into position and the threaded sleeve is again screwed tight.

The tool described above has a number of inherent advantages deserving of special mention. In the -irst place, it should be noted that since the pin plate is rigidly secured to, and bottomed on, the frame 15, the pins may be subjected to large forces without any risk or damage or without risk of cooking of the pin plate. This constitutes a substantial improvement over conventional kickers in which the pin plate is floatingly adjustable with respect to the frame. Moreover, since the adjusting screw is subject to purely axial forces and free of any cooking force, and since the adjusting screw is not subjected to the kicking forces, such screw may be of relatively light and inexpensive construction, easily turned by the linger tips of the user.

It may be noted further that the particular coil spring arrangement produces a novel variation in the restoring force. Initially, when the links 51-53 are more or less vertical, the spring is effective to maintain the guard plate outwardly extended into its protective position as shown in FIG. 3. As the pin plate is swung inwardly on the vertical links, the links increasingly occupy a more horizontal, toggled, or on-center position, so that a relatively light force suiiices to maintain the guard plate bottomed against the stop surface 81 at the end of the adjusting screw.

Because of the cut outs or throats provided along the forward and rear edge of the pin plate it will be apparent that not only the links but also the mounting portions 61, 62 and 73, 74 of the guard plate may be accommodated within the plane of the pin plate, thus permitting a high degree of compactness and maximum available extension of the pins. Stated in other words, adequate pin extension may be obtained even though the guard plate is relatively massive and even though relatively short, sturdy pins are employed.

A further feature of the device resides in the fact that it has an attractive, uniiied appearance in spite of the relative movement between the frame and the guard plate which is arranged below it. Unification is achieved by nesting the walls 16, 48 of the frame and guard plate. It will be apparent to one skilled in the art that this nested relationship may, if desired be reversed by increasing the size of the frame proiile so that the wall 16 becomes an overlapping wall.

While the invention has been described in connection with a kicker, it will be understood that the construction of the head is not limited to use with a tool of a kicker type and if desired, the handle 11 may be extended, for example, to the opposite wall of the room, and provided with means for thrusting tubes 111, 112 outwardly with respect to one another to apply the stretching force to the head.

While the term plate has been employed in the following claims in reference to the member 30 which mounts the pins and the member 40 which performs the guarding function, it will be apparent that such term has been employed for convenience only and that the term is applicable to any members performing pin supporting, or guarding, functions respectively, regardless of horizontal dimension. Moreover, if desired, the pin plate may form an integral part of the frame without departing from the invention. The term stop, as applied to the means interposed between the frame and the guard plate for limiting the degree of relative extension of the pins beyond the guard plate, has been employed for convenience only to cover means for positioning the guard plate in its working position. The term substantially used in the follow- 6 ing claims with respect to the degree of pin projection is employed to indicate that the tips of the pins need not lie in a precise plane to practice the invention but need only engage the carpet at about the same level.

I claim as my invention:

1. In a stretcher for stretching carpet having a pile and a backing, the combination comprising a frame having a pin plate mounting a set of sharpened carpet-engaging pins arranged side by side at an angle to the plate and rigidly secured thereto with the tips thereof lying substantially in a horizontal plane, a guard plate arranged below the pin plate, said guard plate being at least substantially coextensive with the pin plate and having openings for clearing the pins, means for coupling the guard plate with respect to the frame for broadwise movement of the plate relative to the plane of the tips, means including an adjustable stop interposed between the frame and the guard plate for limiting the degree of relative extension of the pins beyond the guard plate when the guard plate is seated on the carpet thereby to determine the degree of penetration of the pins into the carpet for engagement with the carpet backing, and means for applying combined longitudinal and downward force to the frame.

2. The subject matter of claim 1 in which a parallelogram linkage is provided for securing the guard plate with respect to the frame for maintaining the guard plate parallel to the plane of the tips in its various positions of adjustment.

3. The subject matter of claim 1 in which a biasing spring is provided for maintaining the guard plate in an extended position for shielding of said tips during periods of non-use together with a stop for deiining said extended position.

4. The subject matter of claim 1 in which the adjusting means for the guard plate includes a screw threaded with respect to one of the plates and having a bottoming stop surface thereon for engaging the remaining plate.

5. The subject matter of claim 1 in which the openings in the guard plate are in the form of longitudinal slots, and in which the securing means includes vertical links rocking about transversely extending axes for guiding the guard plate toward and away from the pin plate while maintaining parallelism between them, and means including a spring for biasing the guard plate outwardly with respect to the pin plate.

6. The subject matter of claim 1 in which the guard plate is provided with parallel vertical links pivoted on transverse axes for coupling the same to the pin plate for movement inwardly and outwardly with respect to the pin plate and in which the guard plate is outwardly biased having a iirst stop for limiting outward movement and a second stop for limiting the inward movement thereby to control the degree of extension of the pins when the guard plate is pressed into contact with the carpet under working conditions.

7. The subject matter of claim 1 in which the frame and guard plate are nested with respect to one another and in overlapping engagement within the range of relative adjustment.

8. The subject matter of claim 1 in which the plates are interconnected by a set of parallel links and in which at least one of the plates is relieved adjacent the links for accommodation of the links when the guard plate is swung to a position closely adjacent the pin plate.

9. In a stretcher for stretching carpet having a pile and a backing, the combination comprising a frame having a pin plate integral therewith mounting longitudinal rows of sharpened carpet-engaging pins set at an angle to the plate, a guard plate arranged below the pin plate and having slots for accommodating the respective rows of pins, means for adjusting the relative spacing between the guard plate and the pin plate thereby to adjust the degree of extension of the pins, said guard plate having an undersurface lying substantially in a plane and having upraised 7 8 lands extending beyond said plane at the edges of the slots, References Cited said landsr occupying a minor fraction of the guard plate UNITED STATES PATENTS area so that the lands are submerged in the pile to a depth adjacent the backing when downward force is applied incident to normal use ofthe stretcher to dene a more posi- 5 2882642 4/1959 H111 2948'6 tive reference surface for gauging the degree of extension y.

of the tips of the pins, and means for applying combined GERALD M' FORLENZA Pnmary Examiner' downward and longitudinal force to the frame. F. E. WERNER, Assistant Examiner.

2,606,743 8/1952 Owens. 

1. IN A STRETCHER FOR STRETCHING CARPET HAVING A PILE AND A BACKING, THE COMBINATION COMPRISING A FRAME HAVING A PIN PLATE MOUNTING A SET OF SHARPENED CARPET-ENGAGING PINS ARRANGED SIDE BY SIDE AT AN ANGLE TO THE PLATE AND RIGIDLY SECURED THERETO WITH THE TIPS THEREOF LYING SUBSTANTIALLY IN A HORIZONTAL PLANE, A GUARD PLATE ARRANGED BELOW THE PIN PLATE, SAID GUARD PLATE BEING AT LEAST SUBSTANTIALLY COEXTENSIVE WITH THE PIN PLATE AND HAVING OPENINGS FOR CLEARING THE PINS, MEANS FOR COUPLING THE GUARD PLATE WITH RESPECT TO THE FRAME FOR BROADWISE MOVEMENT OF THE PLATE RELATIVE OF THE PLANE OF THE TIPS, MEANS INCLUDING AN ADJUSTABLE STOP INTERPOSED BETWEN THE FRAME AND THE GUARD PLATE FOR LIMITING THE DEGREE OF RELATIVE EXTENSION OF THE PINS BEYOND THE GUARD PLATE WHEN THE GUARD PLATE IS SEATED ON THE CARPET THEREBY TO DETERMINE THE DEGREE OF PENETRATION OF THE PINS INTO THE CARPET FOR ENGAGEMENT WITH THE CARPET BACKING, AND MEANS FOR APPLYING COMBINED LONGITUDINAL AND DOWNWARD FORCE TO THE FRAME. 